Fluid pressure governor



July 14, 1931. 11.1w 1,814,631

FLUID PRESSURE GOVERNOR Filed June 15, 1928 V G3 3 62 g 52 39 1'1 1 Q32l5 4 QE 4 49 29 4 55 45 a 31 51 4 3 4 5| 4| z u I 11 I 5 3 1:: 2: a: s2,

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WITNESSE I 4 J I I E v 6. I n Y I fi BY QXPQ ATTORNEY Patented-Jul 14,1931 UNITED sTATEsrAT'ENT OFFICE v JAMES L. RAY,'OI' SWARTHMOBE,PENNSYLVANIA, ASSIGNOR T WESTINGI-IOUSE ELEC- TRIC & MANUFACTURINGCOMPANY,

A CORPORATION OF PENNSYLVANIA FLUID rnnssunn GOVERNOR Application filedJune 15,

My invention relates to governors, more particularly to fluid-pressuregovernors for prime movers-and it has for its ob ect to provide agovernor affording improved reg- Inaccordance with my invention I pro-.

deflection.

I also. provide, in accordance with my in: vention, a pressuretransformer of simple and inexpensive design.

Apparatus exemplifying my invention is.

illustrated in the accompanying drawings, in which: I

Fig. 1 is a diagrammatic view of my governor as applied to a primemover, with the parts thereof shown in section; and

Fig. 2 is a sectional view of a modified form of pressure transformer.

Referring to the drawings in detail, I show a turbine 10 having a steamchest 11 and a shaft 12. A pump is provided which includes a casing 13andan. impeller 14 mounted 1928. Serial No. 285,673.

directly on the shaft 12. The pump is supplied with fluid, preferably aliquid, such as lubricating oil from a reservoir 64 through a conduit65, and'provides a fluid ressure varying as the square of'the spec ofthe shaft 12, as is well known of centrifugal pumps. The pressuredeveloped by the pump is transmitted through a conduit 15 to apressure-transforming device 16.

The device 16 includes a casing 17 having a partition 18 thereindividingthe easing into two compartments 19 and 2], Abore portion 22 isformed in the partition 18, and loosely fitted in this bore portion is apiston portion 23 which is an integral extension of a pressure-reliefvalve 24. Asmall passage 25 also extends through the partition 18 and isdisposed in close proximity to the bore portion 22. An adjustable needlevalve 26 provides. a restricted orifice 27 in thepassage 25. The conduit15 communicates with the chamber 21 of the pressure transformer andsupplies governing fluid pressure thereto, which pressure is effectiveon thelower end of the piston portion 23.

The passage 25 communicates with an annular groove 29 in. the partition18, said groove being concentric with the bore 22. The valve 24 has aflange 31, which seats on the partition 18 outwardly of the groove 29,and which forms a recess 59 with the piston portion 23'. The valve 24 isbiased to closed position by a compression spring 32, interposed betweenthe valve and a spring holding member 62. The position of the latter maybe adjusted by a screw 63 to vary the force exerted by the spring 32. Apassage 33 is formed in the partition 18 and provides communicationbetween the groove 29 and a conduit 34.

The conduit 15 communicates with a branch conduit and the conduits and35 communicate with a relay valve casing 36 I which returns thedischarged fluid to the reservoir 64. The casing is further providedwith ports 43 and 44, communicating with the 11 per and lower ends,respectively, of a cylin er 45 in which isdisposed an operating piston46, The pistonf46 is connected to and operates the valves of the steamchest 1 1 through any suitable means, such means being here shown as arod 47.

A pilot valve 48 is disposed and operates within the cylindrical casing36. The pilotvalve is provided with piston portions 49 and \51 whichnormally covertheports 43 and 44, respectively. Piston portions 52 and53 are also provided at the ends of. the pilot valve beyond thedischarge ports 39 and-41,..re-

specti'vely; The pilot valve 48 is formed with a hollow interior and isclosed at the upper end. A tension spring 54 isdisposed within thehollow interior, having one ,end secured to the closed upper end-of thepilot valve and having its other end secured to the upper end of a stem55, which extends through thelower end of the casing. The

stem 55 is connected at its lower end to a lever-- 56 intermediate theends of the latter. The

lever 56 isconnected at one end to a station ary pivot 57, and at itsother end is to the rod 47 as indicated at 58. n

Thedrain conduit 42 also communicates with the chamber 19. r

The operation of this embodiment of-my invention is as follows:

pivoted The pump provides a governing fluid pressure which istransmitted to the lower end of the relay casing 36 and biases thepilotvalve 48 upwardly against the force of the spring 54.

The governing fluid pressure 'is also transmitted to the chamber 21 ofthe pressure transformer 16, and a small quantity thereof flows throughthe passage 25 and the re,- stricted orifice 27 to the groove 29. 1

The upper end of-the cylindrical casing 36, the conduit 34, the passage33, the groove 29, and the recess 59 provide anenclosed,

space in which thefluid flowing to the groove 29 is received. Therestricted flow of fluid. into this space is controlled by adjustmentof. the needle valve 26. and builds up the pressure thereinuntilthepressure in the recess 59 acting on the valve 24, together with thegoverning fluid pressure onthepiston 23,

overcomes the force of the spring 32, when the valve 24 liftsand permitsescape of fluid from the enclosed space to the chamber 19;

sure, the increased pressureacting'on the piston 23 raises the valve 24slightly, permitting fluid to escape from the enclosed space until thepressure therein is reduced to offset the increased force exertedagainst the spring 32. Upon a decrease in governing fluid pressure,pressure on the piston 23 is reduced and the spring 32 moves the valve24 to closed position until the pressure in the enclosed space builds upto again balance the spring 32 together with the pressure on the piston23.

Upon an increase in speed of the prime moverthe pressure developed bythe pump increases", increasing the pressureacting on the lower end ofthe pilot valve 48 and decreasing the pressure acting downwardly on theupperend. The sum of these pressure changes moves the pilot valve 48upwardly until theincreased tension of the spring 54 equals the sum ofthe pressure changes. The port 43 is now in communication with the port37, and fluid pressure is supplied to the upper end of; the cylinder 45,m0vi-ng the piston 46 downwardly to close the valves'in the steam chest11. The port44 is placed in communication with the discharge port .41

and the fluid beneath the piston 46 is dis-. v

is decreased bya force-equal tothe sum of the pressure changes, The port44, is placed in communication with the pressure supply port 37 andtheport 43 is placed in communication withthe-discharge port '39. Thepiston 46, therefore, moves upwardly to open the valves in the steamchest, and the leverv 56. moves upwardly until the piston portions 49and. 51 again cover the ports 43 and 44. i

The speed setting of thegovernor maybe changed by turning the screw. 63to vary the;

force-of the spring 32, and,therefore, the value of the fluid pressurein the enclosed vFrom the above description it will be apparent that Iprovide greater variations in the fluid-pressure acting on the pilotvalve 48, whereby adequate movements of the operat- The pilot valve 48,moves downwardlyuntil the spring tensioning piston 46 may be obtainedfor a given j change in speed. .It will also be notedthat by increasingthegovern-ing action on the pilot valve 48, a greateropening of. theports'43 I and .44, andhence a'morerapid operation of 1 the steam chestvalves, 15 obtained. Upon an increase in governing fluid pres- Referringparticularly to the pressure transformer, it "will be noted. that itisof It is also pointed out that the variations in fluid pressure abovethe pilot valve may be greater than the variations in the governingfluid pressure, and that the ratio thereof is determined by the inverseratio of the areas in the pressure transformer on which the fluidpressures act. In the device shown on the drawing, for example, the areaof the piston portion 23 is approximately twice the area of the-recess59. Upon a given change in the governing fluid pressure acting upon thepiston portion 23, therefore, there must be twice as great a variationin the fluid pressure in the recess 59 to offset the change in forceopposing the spring 32. It is thus possible, by a choice of said areas,to obtain any magnitude of pressure variation on the pilot valve 48 fora given change in speed.

In Fig. 2, I show a modified form of pressure transformer 16, in whichthe governing fluid pressure is admitted through a conduit 15 and anorifice 61, and applied to a central recessed area 23 of a relief valve24. A restricted flow of fluid passes from the conduit 15 through anorifice 27 to a conduit 34 and to an annular groove 29 in the casing17',

where its escape is controlled by the relief valve 24'. Fluid escapingfrom the recessed portion 23 and from the groove 29, is discharged to adrain conduit 42.

The operation of the pressure transformer 16 is similar to that of thedevice shown in Fig. '1, a pressure varying inversely with the governingfluid pressure being transmitted through the conduit 34.

While I havecshown' my invention in several forms, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various other changes and modifications, without departing from thefrom said enclosed space and thereby controlling the pressure thereininversely to the first-mentioned fluid pressure, valve operatingmechanism for controlling the admission valve and including a pressureresponsive element and a spring biasing the element. said mechanismoperating upon change in spring deflection to provide a valve movementproportional to the change in spring deflection, means for applying thefirst-mentioned fluid pressure to the pressure responsive element invalve closing direction,

and means for applying the fluid pressure in said enclosed space to saidelement in opposition to the first-mentioned fluid pressure so that thevariations in the former fluid pressure assist the variations in thelatter fluid pressure to provide increased spring deflection andconsequent increased valve move ment.

In testimony whereof, I have hereunto subscribed my name this 7th day ofJune, 1928.

JAMES L. RAY.

